This was a tricky one. It would have been easier to understand if nothing worked, but to have only the eye position scene work, that is strange.
If you run the free demo game again it still works as expected? It is only the EyeX demo scenes in the SDK that do not work?
How about if you open the EyeX -> Settings -> Test eye tracking, the gaze trace is plotted normally there?
Does the EyeX Interaction feature Mouse Warp works (move your mouse slightly in the desired direction, and it jumps to where you are looking)? (Available under EyeX -> Settings -> Pointer Interaction).
Have you tried all the basic stuff like unplugg/replug the eye tracker, restart EyeX, restart computer, and such?
Any more input on what seems to work and not work would be helpful.